Streptomyces flavogriseus cellulase: Evaluation under various hydrolysis conditions

Streptomyces flavogriseus CMCase and Avicelase were very stable at 30 degrees C but not at 40 degrees C or higher. beta-Glucosidase was less stable at all temperatures tested. Stabilities were similar at pH values between 5.5 and 7, the optimal range for enzyme activity. Cellulose solubilizing activity was reduced by 40% at a cellobiose concentration of 150 mM but glucose inhibited activity by only 10% at this concentration. beta-Glucosidase was inhibited by 40% at a glucose concentration of 10mM (ten times the substrate concentration). Relatively dilute S. flavogriseus cellulase extensively hydrolysed acid-swollen cellulose at concentrations as high as 10%. More highly crystalline forms of cellulose were more resistant to attack.